1. Technical Field
The present invention generally relates to an apparatus and method for preventing an error in a physically unclonable function (PUF) and, more particularly, to an apparatus and method that prevent a bit error in a static random access memory (SRAM)-based PUF.
2. Description of the Related Art
Generally, even if a manufacturing process is performed in the same semiconductor process conditions, variations in physical or electrical parameters unpredictably occur in each device.
A physically unclonable function (also referred to as a “PUF”) may be applied to devices that yield unpredictable results. In this way, a device to which a physically unclonable function, that is, a PUF, is applied may be used for a device authentication function, a forgery prevention function, etc., as in the case of Korean Patent Application Publication No 10-2014-0059485 entitled “Device Authentication Apparatus and Method using physically unclonable function”).
Recently, among PUFs, an SRAM-based PUF having unpredictability and excellent characteristics from the standpoint of entropy has attracted considerable attention. However, even an SRAM-based PUF is disadvantageous in that robustness thereof is not perfect. To solve this problem, robustness has been improved by connecting an error correction coding PUF to an existing PUF.
An SRAM PUF has a bit error rate of about 6%, so that an error correction code having a high error correction rate must be used. Further, an error correction code having a high error correction rate has a large overhead regardless of whether it is implemented using hardware or software.
Therefore, technology for preventing a bit error in an SRAM-based PUF is required.